CANON IMAGE RUNNER UPPER LEFT SIDE COVER ERROR

I had a customer this past week with this error. I tried resetting the issue… that didn’t work… I then pulled of the back covers and disabled all the trays by disconnecting cables. The error went away. I then reconnected the cables error came back. I then went and disabled the trays one by one by disconnecting cables. I verified which tray was disabled by trying to copy from all trays one at a time. Eventually I narrowed it down to tray three. I then reconnected tray three and it gave me the error. I examined the gears the motor everything. Eventually, I took a close look at the left side cover on tray three. It was slightly out of place. Not enough to be noticed. I closed it tightly. The issue went away. The moral of the story. Don’t over think the problem but if you do then remember not to do that again.